Well you know whats first on Troubleshoot list Tubes. Some power tubes tend to pop when standby switched on. I installed Matched 4 new TAD 6L6 in my Stereo 2:90 and a loud pop, and I see the purple gas flash with the rush of high voltage.
I install a Matched set of JJ 6L6 and the pop is reduced by about 75%... Another tip on the Mesa Stereo Simul-Class 2:90 is switch on the Half Power before power up then go to your regular settings after you switch standby on, it will reduce all popping to near Zero..
I install a Matched set of JJ 6L6 and the pop is reduced by about 75%... Another tip on the Mesa Stereo Simul-Class 2:90 is switch on the Half Power before power up then go to your regular settings after you switch standby on, it will reduce all popping to near Zero..
